from sys import argv
script, input_file = argv
def print_all( f):
 print f. read()
def rewind( f):
 f. seek( 0)
def print_a_line( line_count, f):
 print line_count, f. readline()
current_file = open( input_file)
print "First let's print the whole file: \n"
print_all( current_file)
print "Now let's rewind, kind of like a tape."
rewind( current_file)
print "Let's print three lines:"
current_line = 1
print_a_line( current_line, current_file)
current_line = current_line + 1
print_a_line( current_line, current_file)
current_line = current_line + 1
print_a_line( current_line, current_file)